1 Open a world composition persistent level and load its sublevels containing respective landscape streaming proxy.
2 Use landscape change component size tool with resize mode to resample, then Apply
Results: The resample works but it merge all data in sublevel into the landscape actor in persistent level.
Expected Results: The resample works and it keeps the tiled landscape data in their respective sub level.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-84992 in the post.